There is a nail driver provided with a manual type adjuster for adjusting a driving depth so that a surface of a head portion of a nail that has been driven by the nail driver is in plane with a surface of a counterpart member (hereinafter referred to as “drive-receiving member”) into which the nail has been driven. For example, a nail driver described in Japanese Patent Application Laid-Open No. 2004-351523 (Patent Document 1) includes an adjuster for adjusting a length of a push lever that abuts against a drive-receiving member, the adjuster by which a protrusion amount from an injection hole on a tip of the push lever of a driver blade that hits the nail is adjusted so as to adjust a driving depth.
Also, when the driving depth is adjusted by using the adjuster, a pressure of compressed air supplied from a compressor is used in a highly-adjusted pressure state often, and therefore, there is a problem that a life of the nail driver is shortened due to energy (excess energy), which has not been used for driving, among driving energy of a piston.